How does the framerate vary when you move closer and further away from the particles/lights?I can imagine that the framerate would go down rather quickly when each light takes more space on the screen.... Assuming you're using deferred lighting or something like that, which you most likely are ;)

... because for lights this small the result is visually indistinguishable from just drawing a bunch of additive particles to represent the light glow.

I guess I don't see a compelling use case for this. A sufficiently large number of un-shadowed lights turns into a complex ambient term, which can almost certainly be represented in a far more compact and efficient form ... unless you're planning on somehow carefully placing those lights to approximate a larger occluded light source. But at that point ... have you gained anything over a single shadowed light?

SIGGRAPH paper: this should be released on the Bungie website at some point. I don't know how long it will take. We are currently on the NVIDIA GPU conference showing off the demo. If you want to drop by our booth please come by. The lowest framerate in the whole level is 158 fps. This is the worst case scene.We tested with two GPUs. The one you see here is a GeForce 285 GTX. The lowend GPU we used is the 9600 GT because it has a similar characteristics as the 360 and PS3. On this GPU the lowest framerate in here is about 40 - 50 fps.The scene has several lights with shadows. You just can't see them.

Usually there are a dozen lights with shadows. I will show off a video at some point.

<<<A few shadowed lights > 8000 unshadowed lights<<<This is true but you are starting from the wrong assumptions. You can have a few hundred lights in a level and use a cached shadow map system. So the shadows are only attached to the lights that are visible. I wrote about it on this blog. Look for cached shadow maps.

The lighting is full-res. So the light buffer is not a quarter size.

Brian: if you can live with this and you don't see the advantage of what we do here then this is good for you.

In general we run all the physics and rendering on one GPU here. So the particle with lights bounce from walls.

So far I think we use probably 20 - 30 lights with shadows in one level. Those are not cached but running the whole time.

In case GDC accepts my proposal I want to demonstrate a system that is capable to show off 100's of uncached shadows attached to lights on the next GDC. If not you might stop by our booth and see a demo of this at GDC in March next year.

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About Me

Wolfgang is the CEO of Confetti. Confetti is a think-tank for advanced real-time graphics research and a service provider for the video game and movie industry.
Before co-founding Confetti, Wolfgang worked as the lead graphics programmer in Rockstar's core technology group RAGE for more than four years.
He is the founder and editor of the ShaderX and GPU Pro books series, a Microsoft MVP, the author of several books and articles on real-time rendering and a regular contributor to websites and the GDC. One of the books he edited -ShaderX4- won the Game developer Front line award in 2006.
Wolfgang is in the advisory boards of several companies. He is an active contributor to several future standards that drive the Game Industry.
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